Hello, I have a barn full of the original Showco speakers used by Led Zeppelin, 3Dog night, and The Who in their early years. I have a letter from the President of Showco, Charles Kitch of authenticity.
If you are interesting contact me for pictures or a visit. I have had these for many years and these are the only remaining units left that I know of. Mid bass chambers, tri-flex horns, JBL horns, and other assorted enclosures all used by these groups.